1. Field of the Invention
This invention relates to a method and apparatus for recording and reproducing X-ray pictures through the utilization of a housing which contains a recording medium which is sensitive to X-rays.
2. Description of the Prior Art
In order to improve the picture quality and the contrast in the recording of X-ray pictures, in comparison to conventional photographic plates, it is already known in the art to employ so-called "xeroradiography" techniques in which the X-rays strike a layer which has already been charged prior to the exposure and consisting of, for example, of amorphous selenium having a high dark resistance characteristic. In the selenium, the X-ray quanta produce high-speed photo electrons which, in turn, produce pairs of electron holes, resulting in a breakdown of charge. The layer is developed by being dusted with a cloud of powder, consisting, for example, of toner particles, whereupon the tone impage is transferred by an electric field to lined paper and is fixed by a heat treatment.
Another possibility consists in arranging this X-ray sensitive layer in a chamber which is filled with an inert gas under pressure, and then exposing the layer to the X-rays. In this case, the layer is not charged prior to the exposure with the X-rays, as in the inert gas process, for example, in xenon, the X-rays produce an ionization current so that each quantum releases a photoelectron giving rise to pairs of electrons-ions which build up a charge on a charge carrier layer. In order to develop the X-ray picture, the gas must now be eliminated from the chamber, the plate must be withdrawn, and then, similarly as in a "xerography" process, the plate must be dusted with a powder and fixed by heating. It will be clear from this complicated development process that only low picture rates can be achieved, and that there can be no question of a radioscopy process in the form of series investigations.